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		<title>emde</title>
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		<h1 id="emde">eMDE</h1>
		<p>eMDE is a component with a top-level metamodel which enables to support metamodel extensions by aggregation. This component is essentially used for viewpoint development.</p>
		<h2 id="concepts">Concepts</h2>
		<h3 id="extension-by-inheritance">Extension by Inheritance</h3>
		<p>EMF enables extensibility only by sub-classing existing classes (see picture bellow). This mechanism enables inheritance of all properties, constraints, and representations (e.g., user interfaces, diagrams). But the type of a model element cannot be changed during its lifecycle.</p>
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			<img alt="Extension by Inheritance" border="0" src="img/emf_extension.png"/>
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		<h3 id="extension-by-aggregation">Extension by Aggregation</h3>
		<p>Kitalpha introduces the mechanism of extension by aggregation, the same model element can be decorated by data from different concerns (i.e. viewpoints).</p>
		<p>The picture bellow shows how eMDE introduce the extension by aggregation. Conceptually, ClassA aggregates ClassB and ClassC.</p>
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			<img alt="Extension by Aggregation" border="0" src="img/emde_extension.png"/>
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